Circuit controller



Oct. 29, 1946. H. L. LAMBERT 2,410,085

GIRCUIl CONTROLLER Filed Jane 26, 1945 2 \sneetssheet 1 ATTORNEYS Oct.29, 1946. H. LAMBERT 2,410,085

CIRCUIT CONTROLLER Filed June 26, 1945 2 Sheets-Sheet 2 y, 14M @miATTORNEYS Patented Oct. 29, 1946 UNITED STATES PATENT OFFICE CIRCUITCONTROLLER York, N. Y.

Application .lune 26, 1943, Serial No. 492,395

13 Claims. 1

This invention relates to circuit controllers, and particularly to thosewhich are responsive to centrifugal forces for their operation.

In my prior Patents No. 2,301,217, issued November l0, A1942, and No.2,333,533, issued November 2, 1943, I have disclosed several forms of amercury tube switch which may be employed to control a circuitselectively in accordance with centrifugal forces acting upon a globuleor small body of mercury or other conducting liquid contained within aclosed chamber. prior devices the circuit controlling action can only beadjusted by shifting the tube switch bodily to dilerent distances fromthe axis about which it is bodily rotated Vin use.

An object lof the invention is to improve the adjustment of mercury tubeswitches of the type that are responsive to centrifugal forces so as tocausethem to operate at different speeds.

Another object of this invention is to provide,

an improved centriugally operated circuit controller utilizing a mercurytube switch, with which any adjustment to operate at different speedsmay be made in a simple manner, and with considerable accuracy.

Another object of the invention is to provide an improved speed controlfor an electric motor, with which the maximum allowed speed for themotor may be varied within substantial limits by simple adjustments.

Another object of the invention is to provide an improved, centriiugallyoperated circuit controller havingsimple and novel means for varying thespeed of rotation at which it will open orclose a circuit, which may beeasily andv quickly adjusted to vary the speed at which it becomeseffective, and which will be relatively simple, compact, dependable,durable and inexpensive.

Another object of the invention is to provide an improved circuitcontroller which may be utilized to control a circuit; `at any of aplurality of selected speeds, with which the device may be maderesponsive to one speed or another by simple manipulations, with whichthe change in selected speed limits may be made without stopping theoperation of the controller, and which will be relatively simple andinexpensive.

Another object of the invention is to provide an improved, centriiugallyoperated, mercury tube switch which may. by its mounting with respect to`the axis of rotation, be caused to operate at different yspeeds of suchrotation.

Other objects and, advantages will be apparent from rthe followingVdescription of some embodi- In all of saidv ments oi the invention, andthe novel features will be particularly pointed out hereinafter inconnection with the appended claims.

In the accompanying drawings:

Fig. 1 is a side elevation of a circuit controller constructed inaccordance with this invention and illustrating one embodiment thereof,a. portion of the mechanism being broken away to snow interior parts;

Fig. 2 Vis a transverse, sectional elevation of the same, the sectionbeing taken approximately along the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal, sectional elevation through a mercury tubeswitch forming part of this controller, and of the type shown in Figs. 1and 2;

Fig. 4 ,isl a longitudinal, sectional elevation through another type ofmercury tube switch that may be employed in the controller of Figs. 1and 2.

Fig. 5 is a transverse, sectional elevation through the device of Fig.f1;

Fig. 6 is a longitudinal, sectional elevation of a normally open circuittype of mercury tube switch which may be also employed in the controllerof Figs. 1 and 2;

Fig. 7 is an end elevation of the same;

Fig. 8 is a longitudinal, sectional elevation of still another type ofmercury tube switch that maybe employed in thecircuit controller ofFigs. 1 and 2;

Fig. 9 is an end elevation of thel same;

Fig. 10 is a vschematic wiring diagram showing a motor in series withand controlled by a circuit controller constructed in accordance withthis invention and having three possible selections of maximum speeds;

Fig. 11 is a schematic diagram showing one possible .circuit in which asmall controller of the type shown in Figs. 1 to 4, 8 and 9 may beeinployecl to control the speed of operation of a motorwith quick changebetween two possible but variable maximums;

Fig. 12 is a similar diagram illustrating how a normally open circuitswitch of the type shown in Figs. 6 and 7 may be employed in thecontrol- 1er mechanism of Figs. 1 and 2 to control the speed ofoperation of a motor at either of two possible selective speeds.

In the embodiment oiv the invention illustrated -in Figs. 1 to 3, thecontroller is rotated bya shaft t, which may be a moto-r shaft or anyother rotatable element extending loosely through a block 2 of suitableinsulating material. vA plate 3 of insulating material is provided witha metallic sleeve having 4a collar 4 which telescopes over and issecured upon the end of the shaft I in any suitable manner, such as by aset screw 5 passing through the collar 4 and engaging the shaft I. Thecollar 4 spaces the plate 3 and the block 2, and upon the race of theplate 3 towards the block 2 are a. plurality of concentric collectorrings 6, I and 8 which may be countersunk to some extent into the faceof the plate 3. These rings are secured to the plate for rotationtherewith in any suitable manner, such as by studs 9 passing through theplate 3 and the collector rings. The studs 9 have shouldered, reducedends which pass through apertures in the collector rings, with the freeend beyond the ring upset, and the other ends of the studs 9 are alsoshouldered and reduced and have riveted thereon spring contact, metalarms I0. The collector rings on one face of the plate 3 and the contactarms I on the other face of the plate 3 prevent endwise movement of thestuds 9 in the plates 3 and definitely anchor the collector rings 6 andl to the plate 3.

A pair of spring clamp arms Il and I2 are disposed face to face, butspaced with relation to one another, with their corresponding endsparallel and connected by bolts I3. Between their ends, these arms IIand I2 are made oppositely concave at corresponding zones oi theiradjacent faces so as to form between them a socket which receives thebase I4 or body of a mercury tube switch. In this particular example,there are two of such sockets, one formed adjacent each end of the unitformed of the pair of arms II and I2, and each of which sockets mounts amercury tube switch. These switches may also, for convenience, bedistinguished from each other by the letters A and B. By tightening thebolts I3, the arms II and I2 can be brought together so as tofrictionally and yieldingly clamp between them the mercury tube switchesA and B. By loosening the bolts I3, the switches A and B may beindividually rotated about their own axes in their sockets formedbetween the arms II and I2, and then clamped4 in different rotativepositions by retightening of the bolts I3. The central portions of thearms II and I2 are provided with laterally extending lugs or flanges I5which lie at against the adjacent face of the plate 3, and the screws I6pass through these flanges or lugs I5 and into studs IlJa passingthrough the plate 3 and anchored to the central collector ring 8. TheIianges or arms I5 serve in place of the contact arms I0 to preventendwise movement of the studs I0a.

The switches A and B may be similar in construction, and in theparticular example shown, each of these switches is provided with agenerally spherical shell I'I, see Fig. 3, which has an opening in oneside and a short, outwardly extending ange I8 surrounding such opening.This casing I I is made of conducting material not Wet by mercury, suchas a shell made of pure iron, cr of selected alloys. A plate I9 of glasshaving a coefficient of expansion approximately equal to that of themetal of the casing I'I is placed across the opening of the casing I'Iand fused to the flange I8 so as to close the casing II. By closing thiscasing I1 with this glass closure plate I9, it is possible to exhaustthe chamber 20 within the casing I1 of air and replace it with an inertgas, as usual in mercury tube switches.

A conductor 2| extends through the plate I9 of glass into the chamber2U, and within the chamber 20 it terminates in an exposed Contact head22 which is generally spherical, but smaller in diameter than thechamber 20. This head 22 is eccentric to the wall of the chamber 2D, asclearly shown in Fig. 3. In Fig. 3 the axis oi' head 22 is shown by theline 22a, and the axis oi chamber 29 is shown by the line 29a. Theportion of the conductor head 22 within the chamber 2f! and the portionpassing through plate i9 are also made of pure iron or any alloy orconducting material not wet by mercury and having approximately thesaine coeiiicient of expansion as the glass of plate I9. The conductor2i entends some distance beyond the plate I9 and terminates in a head23. Surrounding and telescoping over the periphery of the plate I9 is ametal sleeve or Ierrule 24 which may be electrically connected to thecasing Il in any suitable manner, such as by solder or a small piece ofwelding 25. A disk 28 closes the outer end of this sleeve or ferrule 24and is confined therein by the ilange of the head 23 of the conductor.The chamber within the ferrule 24 is iilled with a suitable insulatingmaterial 27, as usual in electric filament lamp bases.

Within the chamber 20 is disposed a globule or small body 29 of liquidmercury which, when the switch is idle and supported in the positionshown in Fig. 3, will rest upon a side wall of the chamber 20 and touchthe head 22. The globule or body of mercury 28 is of such size that itnormally assumes a somewhat `ball-like form in which a substantialportion thereof is held away from the wall against which it rests, oragainst which it is conlined, by its surface tension acting inopposition to the forces of gravity upon the mercury.

It will be noted from Fig. 3 that the head 22 is much nearer one zone inthe periphery of the side wall oi" the chamber Eil than it is at thedirectly opposite side, because the head -22 is eccentric to the chamber2D. The mercuiy 28 is normally suiiicient in depth to touch the head 22when in the widest portion in the space between the head 22 and the wallof the chamber 2B, as shown in Fig. 3.

When a switch of the type shown in Fig. 3 is mounted between the arms IIand I2` as shown in Figs. l and 2, the arms I I and I2 will grip andclamp the sleeve or ferrule 24, which is electrically connected to thecasing I`I. When the switch is so mounted between the arms l I and I2,the head 23 on the outer end of the conductor 2| will abut against oneof the contact arms I0 and provide an electrical connection between theContact head 22 within the chamber 20 and a collector ring on the plate3, In the examples shown in Figs. 1 and 2, the head 23 of the conductor`2l of the switch A will engage with the arm I!) which is connectedthrough a stud 9 to the collecter ring l, and the conductor head 23 ofthe switch B will engage the contact arm Ill that is connected through astud 9 through the collector ring 5. The sleeves or ferrules I4 of bothswitches A and B will be connected through the arms I I and I2, screw IBand studs Illa tothe collector ring 8.

A plurality of brushes 23, 3G and 3I are mounted in sockets in the block2 and yieldingly urged outwardly by individual springs 32, Suitablecircuit connection are made through the brushes 29, 30 and 3|, so thatthe wire connected to the brush 29 will be connected through that brushto one of the collecting rings. The wire connected t-o the brush 3U willbe connected through that brush to another collecting ring, and the wireconnected through the brush 3l will be connected therethrough to anothercollecting ring. lAny delhasa terminal thereof connected to the commoncollector'ring which is `connected through a brush to a Acircuit wire 33of a circuit to becontrolled. The'other terminal of the switch A is`connected through a brush toa circuit Wire 34 which leads to a switchcontact 35. The other .terminalof the switch B is connected by a wire 35to a switch Vcontact 31, and the other terminal of the switch Cisconnected by a lwire 38 to a switchtcontact 39.

Thesecontacts 35, 31 and 39 are arranged in a 'suitable sequence so asto be engaged selectively one at a time by a contact or'switch arm 40adjustable about a pivot 4I and provided with an operating handle42. Theswitch arm 40 is connected by a wire 43 to one line wire, such as L',the other line -wire L2 being connected to one side of a motor M. Theo-ther'side-of the motor M isconnected to the ywire 33, so that themotor M will be irl-series with one of the switches A, B and C,depending upon the position of the switch con- `tact 40. Each of theswitches A, Band C is in- ,0.

dividually rotated in its socket between arms H and l2 until the portionof .the chamber 2i) there of whichzis farthest from the axis of rotationof the shaft I will be that which ,Willcause separation .of themercuryglobule from the contact 22 yat .a desired speed, whichspeedwillpreferably and usually be different for each of the switches Forexample, the switch A may be set with the widest distance between theContact head 22 and the side wall of the chamber 20 farthest from theaxis ofthe shaft I, so that smaller centrifugal forces will be :required.to ilatten the vglobule of mercury of that switchsuliiciently tointerrupt the current between the globuleand-thecontact head 22. Thismay be designated ,as a low speed. Similarly, the switch B may be 'setby rotating it through a partial revolution about its own axis to placethe Zone of the chamber 2!) having a medium distance between the headand the chamber wall, farthest from the axis of rotation, which would bea medium speed. The switch C may be set for high speed by rotatingitthrough a partial revolution about lits own axis and in its socketuntil the shortest distance between the head and the adjacent chamberwall is farthest from the axis, and larger-centrifugal forces will thenbe required to flatten the globule thereof sufficiently to remove itfrom contact with the head 22. When the shaft l is rotated in thismanner, all of the switches A, B and C will be rotated bodily about thesame axis, and as the machine starts, each of the globules will be incontact with a spherical Ahead 22 and with a casing i1, so thatregardless of whether the.

'switch handle 41. is set in the high, medium or low positions, acircuit for the motor will be closed through whichever switch A, B orCis connected through the switch arm 4i) to the line wire L.

In this example, the shaft l which mounts the plate `3 is, of course,either the armature shaft of the-motor M or a shaft which is driven at adesired speed ratio therefrom. Let it be assumed, for example, that the'switch handle 42"'is set for a medium speed, as shown in Fig. 10.A Thiswill complete a circuit through the wire 36 to the speed for which theswitch B is set. u

is happening the mercury globules in the; other `6 vswitch B .and to themotor M; The motor willV thenv operate and lrotate the plate 3 with theswitches A,`B and C thereon.. Whenthe centrifugal -forces acting on themercury in the Yswitch -B Aare suiiicient to fatten or distortA the.globule `of mercury kthereinagainst its surface tension -until `vitwithdraws from the head v.22, .this will .open the circuit to the motor,whereupon ,the lspeed of the motor will fall. Just zas rsoon as fthespeed `fallsslightly, the `:surface tension of the globule of mercury.in theswitch .B will partially restore to the-globule its former `form.cr .shape and reestablish contact with the head 22 in .the .switch.B,thus recompleting the circuit through the motor M. The circuit of themotor M .-willbe automatically opened at theswitch B as soon :as the'speed reaches a selected speed, and will Abe reclosed as soon asthespeed fallsslightly.

The motor willthus be automatically vgoverned to run at a speed lnotexceeding this medium While Vthis switches A and C ywill similarly beattened by centrifugal forces to vary-extents, Abut since .the circuitstherethrough are not completed at switch arm 40they will have noinluence on the motor M- at :this time. When the switch arm '40 isshifted to either low or high position, it will place the switches A orC respectively in the circuit .of motor M, and `:since those switchesare setfor diierent speeds, the circuit of the motor M will be openedwhenever the speed exceeds that speed for Which the switch in vserieswith motor M is set by rotation about its own axis. Thus, while themotor M is running or while it is idle, one may shift the switcharm4.!)fto place the motor M under the control of anyone of the lmercurytube switches A,y B or C. It will be understood, -of course, that anydesired number of switches may be mounted onv the plate 3, andindividually made eiective by a selective swi-tch.

In Figs. 4 :and 5, ,the mercury tube switch is slightly different thanthat shown in Figs. l to 3, in that the housing o-rcasing is made of acylindrical sleeve 44 of pure iron or other grnetal not wet by mercury,whichis closed atits ends by pla-tes'45 and 46 of a glass havingapproximately the same coeiiicient of expansiones the material of whichthe sleeve 44 is made. A con* ductor '41 extends through one of theseglass plates, such as 46, into the chamber 43 within the cylinder-'44,and is received and supported in a recess 49 provided in the inner faceof the other glass plate 45. The portion of the conductor 41 whichpasses through theplate 46 may be made of the -same material as thecylinder 44, so as to have approximately the same coefllcientofexpansionof that of the glass of whichplate 46 is made, and if desired,the .portion within vthe chamber VV48 may be made of a different metalnot wet by mercury which is welded to ti'ieend of the conductor 41, asshown in Fig. fi. rEhe globule or small body of liquid vmercury isdisposed within the chamber 48 as in the-.switch shown in Figs. 1 to 3.

The conductor 41 is eccentric vto the .wail of the chamber 48, that is,to the cylinder 44, the axis 'of the conductor 41 being shown by thecenter line 5| and the axis of the chamber 5B being shown by the centerline 52. Thus, the conductor 41 will be relatively nearer the kWall ofthe chamber 48 at one side, and relatively `farther at the diametricallyopposite side of thenchamber, and the distance from the conductor 41 to`Lthe zones ofthe peripheral wall of the-chamber 48 between these twopoints will vary progressively. The cylinder 44 can be clamped betweenthe arms II and I2 in place of the switches A and B and by such clampingit will be electrically connected to the arms II and I2 in the samemanner that the casing I'I in Figs. 1 to 3 was, through the ferrule I4,electrically connected to the arms II and I2. The outer end of theconductor 41 will bear against a contact arm Il) in the same manner asin Figs. l to 3, so that the type of switch shown in Figs. 4 and 5 canbe substituted for that shown in Figs. 1 to 3 and wil1 function in asimilar manner.

By rotating the cylinder or sleeve 44 in its socket between the arms IIand I2 through a part of a revolution, one may set the switch toposition any zone of the periphery of cylinder 44, against which themercury may be coniined by centrifugal forces farthest from the axis ofthe shaft I. If at any time, such zone is that which has the greatestdistance to the conductor, then two centrifugal forces necessary toflatten the globule and break contact between the globule and the centerelectrode or Contact 41 will be less than when the mercury is conned byccntrifugal forces in some other part of the chamber of the switch.Thus, one may, by merely rotating this switch in its socket, vary thespeed at which the circuit therethrough will be opened.

In Figs. 6 and 7, the mercury tube switch is of the type shown in Figs.1 and 2 of said Patent No. 2,301,217. In that type of switch, thehousing or casing 53 is made generally elliptical in shape and of glass,but one end portion thereof is made reentrant in the form of a tubularpost 54. The outer end of this post is closed by an element 55 ofinsulating material, which may complete the generally elliptical shapeof the exterior of the housing 53. In this particular example, the post54 may be disposed concentrically of the chani- 4ber 56 within thehousing. A conductor 5T passes through the element 55 and along theinterior of the post 54, approximately to the other end of the post,then it passes through the wall of the post into the chamber 5B, whereit terminates as a loop encircling the post but in spaced relation tothe Wall of the chamber and the periphery of the post 54. Similarly, aconductor 58 extends through the element 55 and the adjacent end of thehousing 53 into the chamber 56, and there it terminates as a loop whichencircles the post 54 at that end of the chamber and is largely inspaced relation to both the housing 53 and the post 54.

In this particular example, the planes of the two loops are madeconvergent in one direction, as shown in Fig. G, and both equallydistant from the center of any globule of liquid confined on theperiphery of the chamber wall by centrifugal forces created by bodilyrotation of the casing 53, so that the distance between loops at oneside of the chamber 56 will be less than between the corresponding partsof the loops at the other side of the chamber 56. The distance betweenthese loops will, of course, progressively vary in a directionperipherally of the chamber. A globule or small body 6I of mercury inliquid form is placed within the chamber 56 and its surface tensionacting against the forces of gravity causes this mercury to form asomewhat ball-like form as shown in Fig. 6, in which a substantialportion of the mercury is held solely by its surface tension away fromand against spreading along the wall of the chamber 56 on which it restsor against which it is coniined by centrifugal forces. When a switch ofthis type is mounted between the arms II and I2 in Figs. l to 3 in placeof either of the switches A and B, the elliptical housing 53 will beclamped frictionally in the socket between the arms II and I2, so thatit may be rotated individually in its socket, and about its longitudinalaxis which will be the longitudinal axis of the chamber 56, so as toplace any particular peripheral zone oi the wall of chamber 56 farthestfrom the axis of the shaft I.

When the shaft I is rotated, the mercury 6I will, of course, be moved bycentrifugal forces into the zone of the chamber 56, which is farthestfrom the axis of rotation of the shaft I, and it Will be conned againstthat zone of the wall undivided and relatively immovable, as the shaft Icontinues its rotation. The mercury globule 6I normally is too short tocontact both of the loops 59 and 6U, but as the speed of rotation withthe shaft I increases, the globule 6I will be ilattened more and more,which causes it to increase its length along the chamber 56 until nallyit will electrically connect the loops 59 and 60 and through them, theconductors 51 and 58. The speed and consequently the centrifugal forceswhich are required to flatten or distort the globule 6I until itelectrically connects the loops 59 and 6I) will vary with the distancebetween the loops 59 and 6U at the zone of the chamber 56 Where themercury globule happens to be conilned by such rotation, or by thedistance from the center of the globule and the loop which is farthestfrom the center of the globule. For example, if the housing `53 is sodisposed that the Zone of the chamber 56 having the shortest distancebetween the loops 59` and 60, is farthest from the axis of the shaft I,then relatively low centrifugal forces will be required to Hatten theglobule 5I suiliciently to connect the loops 59 and 50, but if theglobule is confined in the zone of the chamber 56, such as shown in Fig.6, by the centrifugal forces, where the distance between the loops isthe maximum, then a much higher speed will be required to createcentrifugal forces high enough to elongate the globule of mercury to theextent necessary to connect the loops 59 and 60 at that side of thechamber 56. Obviously, the housing 53 may be rotated in its own socketabout its own axis to place any other part of the chamber 56 farthestfrom the axis of shaft I.

In Figs. 8 and 9, still another form of the switch is shown, in whichthe housing 62 is generally of cylindrical shape, but provided with a,reentrant end portion to form a hollow, internal post 63, which post,however, extends the full length of the chamber 64 and is eccentricthereto. A conductor 65 passes through one end of the housing into thechamber 64 and then is wound spirally around the post 63 to the otherend of the chamber B4. A second conductor B6 also enters the chamber 54and is similarly wound spirally about the post 63 in spaced relation tothe Conductor 65 to the opposite end of the chamber 64. Thus, the twoconductors are wound spirally in spaced relation to each other on theperiphery of the post 63 from one end of the chamber to the other. Aglobule or body 6l of mercury is provided in the chamber 64 as for thechambers of all of the other switches described herein, so that nomatter what zone of the peripheral wall of the chamber of mercury may beconfined against it, it will, by its shape, induced by surface tension,normally engage and electrically connect the spaced turns ofA thefcon-yductors 65' and 66.

When the housing E2 is mounted between the arms II and I3 in Figs. 1 and2 in place of the switches A and B, it may be turned about its own axisin the socket formed between the larms II and I2, so as toplace'farthest from'the axis cf the shaft I any desired peripheralzoneof the chamber 64. For example, when the zone of the chamber 54 havingthe greatest distance from the post 63 to the outside wall is placedfarthest fromv the axis', then smaller centrifugal forces will berequired to flatten the globule lo'f mercury sufficient to separate fromonel or both of the conductors 65 and 65 and' open the circuit betweenthem through the mercury. Thus, by rotating the housing 62 about its ownaxis inits mounting between arms II and I2, the speed at whichthe'centrifugal forces will hatten' the globule sufciently to break thecircuit between the conductors 65 and S may be varied.

It willbe understood that in all forms of the switches, thecircuits'through' the switches 'may be opened or closed depending uponthe type of switch, at any selected speed,v and the circuits throughthese switches may' be signal circuits whichY operate-suitable signals;or any' other' desired apparatus, or if they are included inseries withthe motor, or a relay controlling a motor,

they may controll the` speed of the motor and prevent such motorfrcm"exceedir`1g a selected speed, which= speed may ber'varied byrotating the individual switch about its own axis,

In Fig. 11, I have shown diagrammatically 'the control of a motor 63 byeither of two switches of the type shown in Figs. 1 tos, which: maybeso' selected or adjusted that the mo'torspe'e'd' will not exceed theselected speed of eithercf two! predeterminedspeeds.V In this form ofthe invention, a relay is employed for controlling the mo'- tor circuit,so that a relatively large motor may be employed and itsspeedcoiitrolled' 'oy a; relatively smallcapacity, mercury tube' switch.'

In this circuit, theline wire L is connected to a contact 6% of arelay'R' and the-moveable a'i-m` cr contact tof thatrelayis connected'by! awire 'IiV to one terminal ofthe motor @ill The other terminal ofthe motor e8 is'c'onn'ec't'ed by aiwire 12 to the lline wire L2. Theswitch arm 'IQ off' there'- layis yieldingly urged into'open' circuitpositionby a spring 73. The windingf` of therelay-i'sconnected at oneside to the line wireV L2, and at its other sideby a wire i toth'eybrush which bears upon the collector ringl S; sothatfthroug'hthatcollector ring it will be connected to'one terminal ofV each of themercury' tube switches A and B which aremounted' on the plate `3. Theplate 3', in this example, is shown as mounted directly on the shaft Iof the motor Gil, but! it will be'. un-

derstood that the shaft I may be driven froniithe armature shaft" ofthe; motor 63 through a suit'- able speed changing mechanism', ifdesired. The central electrode of the switch A is connected through abrush and collector ririg and a wire 'IB to a contact TI of afswitch is.The central' electrode of the'other switch'fB' is connected through abrushY and collectorring and` a wire 'I9 to another Contact Sloft'heswitch' 18. The switch 89 has a` contactarm il! which may" be' shiftedalternatelybetween the contactsll and 89 so that circuits through theswitchcsYA-and B may be made alternately available, depending uponwhether ahigh or lcw speed control ofthe motor 68 is*` desired..

In: this particular example, the'switch'A should' be rotated in itsmounting until the selected peripheral wall Zone of the chamber thereofAis farthest from the axis of the shaft If togive the'desired highmaximum speed control. The' switch'B should be similarly turned in itssocket until the selected peripheral zone of the chamber is-farthestfrom the axis of the shaft I to give the desired low maximum speedcontrol'.

Tooperate such a system, the liu'ewhies'L and L2 are connected to asuitable source of current, and the switch arm' 8-I is locked toV placeit in contact with the switch contact 'I-i when a low maximum speed isdesired. When the'motcr is not operating, the mercury globule inthevswitch A will complete a circuit through' that switch and hence themovement of the switch arrn` 8|" into engagement with contact `I'IVw-ill complete' a circuit through the switch A and the winding v"Ill" ofthe relay R. This willl attract thefrelay switch-M vand complete acircuit through the Motor 63.

The motor will start its rotation', and the mercury globules in each ofthe switches A andB will `be thrownagainst the peripheral zone of thesidev wall ofthe chamber of thatswitch which is farthest from the axisof the shaft I. As the speed of the` motor increases, the mercuryglobules will. be flattened to increasing extents, and when the globulein switch A iiattens until it withdraws from the contact head 22l ofthat switch, this will open the circuit-tothe winding 74 of the relay,whereuponl switch arm Ti) `ci the relay is released and moved to openposition; This opens theA circuit of the motor and asl the speed thereoffalls, the mercury globule will be returned by its surface tensiontowardits former shape in engagement with the contact head 22 in that chamberandreestablish the circuit therethrough.V This againy enercizes thewindingf 'Ill and recompletes the circuit to the motor G31'. Thus, thespeed of the motor will be` kept below almaximum determined by thesetting lof the switch A in its individual socket `or mounting.

When a higher maximum speed'is permissible; the switch arm- Il-Il isoperatedV to engagethe contact arm- 8% which placesthe switch B insteadof Ain series with the relaywinding and a simi-lar control of the motor68f is obtained, 'except that since the switchl B is set to placefarthest from the axis of shaft I, the wall zone of the switch chamberwhich causes/the' globule toopen the circuit through that switch atafselectedfmaximum-speed. Hence; a higher speed may now be obtained bythe'motory 68 before-the globule in that switch B will beflattenedsufliciently to leave contact withY the head 22 of that-switchand open the circuit of' relay winding 74.

A somewhat similar circuit arrangement is shown in Fig. 12, but thewinding 82 ci' therelay S acts uponV a switch arm` which'is urged intoVclosed positionagainst relayV contact 'by a springa; Anotherdirferenceis that theswitches D and E are oft-he normally open circuittype, such as shown in Figs. 6 and '7. The wire 15 in this instance willbe connected to the switch and the wire I9 will be connected to theswitch D. Withsuch an arrangementfto start the mctor, the line wires Lfand L2 are connected to a source of current, and immediately a circuitis established through the relay switch arm @3 to the motor 58. At thistime, the globule ofmercury in each 0f the switches D'and EwillV be outof contact with the loopsV 59' and Stfsothat the relay windingl 32 willbedeener'gized. he switch arm SI is shifted, however, into engagementwithone of the'contacts I1 or- 88, depending upon whether the lowmaximum speed or high maximum speed is desired.

Assuming that arm 8| engages contact 11, this will establish a circuitfrom the winding 82 of the relay through the switch E. As the speed ofthe motor increases, the increasing centrifugal forces will flatten theglobules 6l of the mercury of both. switches E and E to greater andgreater extents until globule 6| in switch E engages and connects theloops 59 and B0 of that switch when the desired maximum speed has beenreached. This Will complete a circuit through the winding 82 and thelatter will move its switch arm 83 into open circuit position, thusopening the circuit to the motor 68. The speed of the motor then fallsand the reduced centrifugal forces then acting on the globule 6I ofswitch E will be overcome by surface tension of the globule so as topartially restore the former shape of the globule and open the circuitbetween the loops B and SS. This deenergizes relay winding 82, andspring 85 then moves relay switch arm 83 back into closed circuitposition. The motor will then again receive power and tend to build upits speed, but at no time can the speed of the motor increase above thespeed for which the switch E lis set. By shifting the switch arm BI toengage contact Bil, the switch D is made effective in place of theswitch E, and thus a higher speed must be reached before the relayswitch 83 will be opened to prevent further increase in the speed of themotor. The switches D and 3 are, of course, individually rotatable intheir individual mountings so as to set them for the desired maximumspeed at which the circuit therethrough is to be closed.

While mercury is the preferred conducting liquid for the globule orelectrically conducting liquid because of its relatively high surfacetension, any other electrically conducting liquid with substantialsurface tensions is to be considered the broad equivalent of mercury,but when other liquids are employed in place of mercury, the chamberwall and the exposed electrode within the chamber should be of materialsnot wet by the liquid used. Other conducting liquids are usually lessdesirable because they may be subject to electrolytic decomposition bythe electric current passing therethrough. The chambers of each housingor casing, after introduction therein of the conducting liquid ormercury, are exhausted of air and the air replaced with an inert gas toincrease the effective life of the switches. 'I'his is easily done asusual with mercury tube switches, and the use of glass in closing thechambers makes easily possible this exhaustion of air and replacement ofthe air with another gas.

It is believed that the operation and use of the devices which have beenillustrated and described will be clear from the foregoing description,but it will be understood that any of the mercury tube switches shown inFigs. 4, 5, 8 and 9 may be used as the switches A and B instead of thetype shown in Fig. 3.

It will also be understood that various changes in the details,materials and arrangements of parts, which have been herein describedand illustrated in order to explain the nature of the invention, may bemade by those skilled in the art Within the principle and scope of theinvention as expressed in the appended claims.

I claim as my invention:

1. A circuit controller comprising a hollow housing having a closedchamber with a wall not wet by mercury, a body of mercury within andonly partially filling said chamber, resting upon a side Wall thereofand of a size to assume a curved form in which a substantial portionthereof is held away from and against spreading along said Wall, solelyby its surface tension opposing the action of gravity thereon, aconductor extending into said chamber and therein having a contact withan exposed surface area not wet by mercury, eccentric to a transverseperiphery of said chamber and spaced from and so disposed relatively tosaid chamber wall than when said housing is rotated bodily about an axisnormal to the plane of said transverse periphery and eccentric to theaxis of said chamber, .said mercury will be held by centrifugal forcesrelatively immovable and undivided against the zone of said wallfarthest from said axis of rotation and electrically connected to anddisconnected from said con-tact area as it is distorted in shape byvarying centrifugal forces, and a. circuit connection to said mercurywhereby rotary adjustment of said housing about its own axis to placedifferent wall zones thereof farthest from its axis of bodily rotation,will vary the speed of said bodily rotation at which said electricalconnection or disconnection is made.

2. A circuit controller comprising a hollow housing having a closedchamber with a wall not wet by mercury, a rotatable element, a supportcarried by said element and mounting said housing eccentrically of theaxis of rotation of said element for rotation with said element, saidhousing being separately rotatable, about its own axis, on said support,a body of mercury within and only partially filling said chamberrestingupon a side wall thereof and of a size to assume a curved form in whicha substantial portion thereof is held away from and against spreadingalong said wall, solely by its surface tension opposing gravity, aconductor extending into said chamber and having therein a contact withan exposed surface area not wet by mercury, eccentric to said housingaxis, and spaced from said chamber wall whereby when said housing isrotated with said element, said mercury will be confined by centrifugalforces, undivided and relatively immovable against the zone of said wallfarthest from the axis of said element and electrically connected to anddisconnected from said contact area as its shape is varied by theopposing centrifugal forces and surface tension, and a circuitconnection to said mercury whereby the speed at which an electricalconnection or disconnectionis made between said contact area and saidmercury may be varied by adjustment of said housing about its own axison said support.

3. A circuit controller comprising a rotatable element, supporting meanscarried by and rotatable bodily with said element, a hollow housingmounted by said supporting means eccentrically to lthe axis of rotationof said element, additionally rotatable about its own axis in saidsupporting means and having a closed chamber with a wall not wet bymercury, a globule of mercury within and only partially filling saidchamber and of a size tending to assume a generally balllike form, whenresting upon a side Wall thereof, solely by action of its surfacetension in opposition to gravity, a conductor extending into saidchamber and therein having a contact with an exposed surface area notwet by mercury and so disposed eccentrically with respect to saidchamber, and in contact with said globule while said globule isconfined, undivided and relatively immovable, against a zone of saidwall by centrifugal forces created by bodily rotation of said housing 13L with said element, but from which said globule may separate as saidglobule undergoes changes in shape underthe opposing forces of surfacetension and the centrifugal forces due to its bodily rotation, andcircuit connections to said globule land conductor 'whereby the.centrifugal forces necessary to produce engagement or separation of saidglobule and contact will vary with rotation of said housing about itsown axis to vary the wall zone against which the globule is confined bythe centrifugal forces created by the bodily rotation of that housing.

4. A circuit controller comprising a hollow housing having a closedchamber with a Wall not wet by mercury, a. globule of mercury within andonly partially filling saidchamber, resting upon a side Wall thereof andof a size to assume a generally ball-like form solely by its surfacetension acting against gravity, a conductor extending into said chamberand therein having a contact with an exposed surface area not wet bymercury, locatedwith respect to said globule whilethe latter is confinedundivided and relatively immovable against a zone of said wall bycentrifugal forces as said housing is rotated bodily about an axiseccentric to the axis of said chamber, in a positicnto engage with andbe separated from said globule as said globule changes shape under theopposing forces of surface tension and centrifugal forces due to itsbodily rotation, and a circuit connection to said globule, said contactbeing disposed at difierent'distances from different zones of theperiphery of said wall vwhereby when said globule is conned in differentzones around .the periphery of said Wall by said centrifugal forces, thespeedof said bodily rotationy of said housing which will produceengagement or separation of said globule and contact will vary with thewall zone against which the globule is confined by the centrifugalforces set up.

5. The controller substantially as set forth in claim 4, and a rotatableelement, and a support rotating with said element and mounting saidhousing for selective increments of rotation about said chamber axis toplace different zones-of said chamber side Wall farthest from the axisof rotation of said element.

6. A circuit controller comprising a hollow housing having aclosedchamber with a wall not wet by mercury, a small body of mercurywithin and only partially filling said chamber and of a size to assume acurved form in which a substantial portion thereof is held above andagainst spreading along, said wall solely by its surface tensionopposing the action of gravity thereon, a conductor` extending into saidchamber from the exterior of said housing and within said chamber havingan exposed contact area disposed to be engaged by said mercury body orseparated therefrom by changes in shape of said body under the opposingforces of said surface tension and tht`- centrifugal forces acting uponsaid body when said housing is rotated about an axis eccentric thereto,said contact area having portions thereof disposed at different relativedistances from the center of said mercury body while the latter isconfined against different peripheral zones of said wall by centrifugalforces of said rotation, whereby by confining the mercury body,undivided and relatively immovable against different zones of saidchamber around the periphery thereof, the centrifugal forces necessaryto cause engagement or disengagement between said mercury body andcontact area may be varied, and means for connecting said mercury 14body and conductor in series with each other in part of a circuit to becontrolled by the engagement or separation of said body and Contactarea.

'7. The controller substantiallyv as set forth in claim 6, and a supportfor said housing, in which said housing may be turned about its ownaxis, and an element mounting said support for rotation about an axiseccentric to said` housing axis, whereby the housing may be rotatedbodily about the axis of rotation of said element and also additionallyrotated about its own axis to place different zones along the peripheryof said wall farthest from said axis of rotation of said element.

n mercury tube switch comprising a hollow housing having a closedchamber containing an inert gas and with a wall-not wet by mercury, aconductor extending into said chamber and having therein a contact withan exposed surface area substantially eccentric to, anal spaced from,said wall, a globule of mercury within and only partially filling saidchamber and of a size to assumo a generally ball-like form. solely byits eurfacetension acting against gravity, the distancefrom each .zoneof said Wall to said contact being less than the thickness of saidglobule when the globule is resting on said zone, and circuitconnections leading to said globule and said conductor, wherebywhen saidhousing is rotated about an axis eccentric to .said chamber, thecentrifugal forces created by such-rotation will said globule against azone of said wall, and flatten the globule an amount dependent upon thespeed of rotation of said housing, the distance between the Contact andthe zone of the wall against which the globule is conined by centrifugalforces determining the speed at which globuic separates froml saidcontact.

il. A mercury tube switch comprising a ho-llou.1 housing having a closedchamber containing an inert gas and with a wall not-wet by mercury, acontact in said chamber having an exposed surface disposed at aplurality of different distances from different zones of the peripheryof said wall at the intersection of said wall by a piane transverse tosaid chamber and approximately normal to said wall, a globule of mercurywithin and only partially filling said chamber and cf a size to assumegenerallyball-like form solely by its surface tension acting againstgravity, the

distance from different zones of said Wall periphery to said 'contactsurface area varying, whereby when said housing is rotated about an axisnormal to said plane and eccentric to said chamber, said globule will beconfined against that one of the zones of said wall which is furthestfrom the rotation axis, and variably distorted with changes incentrifugal forces as the speed of rotation varies, said globule by itsdistortion engaging with and separating from said contact, and circuitconnections to said globule and said conductor.

lO. A mercury tube switch comprising a hollow housing having a closedchamber containing an inert gas and with a Wall not wet by mercury, aContact in said chamber having an exposed surarea disposed at aplurality of different distances from different zones of the peripheryof said wall at the intersection of said wall by a plane transverse tosaid chamber and approximately normal to said wall, a globule of mercurywithin and only partially filling said chamber and of a size to assume agenerally ball-like form solely by its surface tension acting againstgravity, the distance from different zones of said Wall periphery tosaid contact surface area varying, a

support for said housing in which said housing may be adjusted angularlyabout an axis of said chamber normal to said plane, whereby when saidhousing and support are bodily rotated about an s' s parallel to butoffset from said chamber axis, :d globule will be confined on a zone ofsaid wall p ,riphery which is furthest from said axis of rotation, andas the speed of rotation varies, opposing centrifugal forces and surfacetension of said globule will distort said globule and cause separationand engagement of said globule and contact at selected speeds, whichvaries with the distance io contact from said peripheral Wall Zoneagainst which the globule is then conned, and circuit connections tosaid globule and said conductor from outside said housing.

l1. A mercury tube switch comprising a hollow liom sing having a closedchamber containing an inert gas and with a Wall not Wet by mercuryJ saidwall being circular in the transverse cross section formed by a planecontaining a radius of curva ture of said wall, a contact within saidchamber and substantially eccentric to said center of cur vature notspaced from said wall, a globule of mercury within and only partiallyfilling said chamber, and of a size to normally assume a generallyball-like form solely by its surface tension acting against gravity, andcircuit connectioi'is leading to said globule and said contact from theexterior of said housing, whereby when said housing is rotated about anparallel to, but offset from the axis of said chamber passing throughthe center' of curvature of said cross section of said wall, saidglobule will be conned against said wall at said section in engagementwith said Contact, and as the speed of rotation increases, said globulewill be flattened against said wall to increasing extents until itseparates from said contact.

12. A circuit controller comprising a hollow housing with a closedchamber containing an inert gas and a wall not wet by mercury, wallbeing a closed surface of generation about an axis of said chamber, abody of mercury within and only partially iilling said chamber and of asize ro normally hold a substantial portion of it, by the action of itssurface tension alone in opposition to gravity, in curved forni and awayfrom the zone of said wall on which it may be resting, a conductorwithin said chamber in a position to be engaged by and separated fromsaid body of mercury as said body is conned against the portion of saidWall furthest from said chamber axis when said housing is rotated aboutan axis parallel to but offset from said chamber axis, and ilaitenedagainst said Wall and released to dilerent extents by varyingcentrifugal forces acting on said body and created by its rotation aboutsaid parallel and offset axis, said conductor being disposed atdifferent distances from the center of said body as said body isconfined against difierent peripheral Zones of said portion cf said wallwhich, is furthest from said chamber axis, whereby the speed of rotationat which engagement and disengagement of said body and conductor occurs:may be varied by disposing of said different Wall sones furthest fromsaid axis of rotation and connections to said body and said conductor`from the exterior of said housing.

13. A mercury tube switch comprising a holloul housing having a closedchamber containing an inert gas and a wall not wet by mercury, Said wallbeing circular in transverse cross section, a surface of generation, andarcuate in the generating line intermediate of its ends, a Contactwithin said chamber, extending oblique to the axis of generation anddisposed in spaced relation along said generation axis from the zone ofsaid Wall furthest from that axis, a body of mercury within and onlypartially filling said chamber, confined undivided and relativelyimmovably on a zone of said wall furthest from said generation axis whensaid housing is rotated about another `ais parallel to and offset fromsaid generation axis, and of a size such that its surface tension actingagainst gravity holds it in a curved form with a substantial portionaway from said Wall Zone, whereby the centrifugal forces acting on saidbody, by reason of said rotation, in opposition to the surface tensionof said body will distort saidl body and elongate it in a directiongenerally parallel to said generation axis, said Contact beingpositioned along said generation axis for eiifragement by and separationfrom said body as the distortion of the body varies at selected speeds,

r which speed at which said engagement or separation occurs will varywith the zone of said wall against which said body is confined, and circconnections to said body and said contact from the exterior of saidhousing.

HARRY L. LAMBERT.

